package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.entity.Shop;
import com.hmdp.mapper.ShopMapper;
import com.hmdp.service.IShopService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.CacheClient;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.RedisData;
import com.hmdp.utils.SystemConstants;
import org.springframework.data.geo.Distance;
import org.springframework.data.geo.GeoResult;
import org.springframework.data.geo.GeoResults;
import org.springframework.data.redis.connection.RedisGeoCommands;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.domain.geo.GeoReference;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopServiceImpl extends ServiceImpl<ShopMapper, Shop> implements IShopService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private CacheClient cacheClient;

    @Override
    public Result queryById(Long id) {
        // 缓存穿透  id2 -> getById(id2)等同于this::getById
        Shop shop = cacheClient.queryWithPassThrough(RedisConstants.CACHE_SHOP_KEY,id, Shop.class,this::getById,RedisConstants.CACHE_SHOP_TTL,TimeUnit.MINUTES);


        // 互斥锁解决缓存击穿
        //Shop shop = cacheClient.queryWithMutex(RedisConstants.CACHE_SHOP_KEY,id,Shop.class,this::getById,RedisConstants.CACHE_SHOP_TTL,TimeUnit.MINUTES);

        // 逻辑过期解决缓存击穿
        // Shop shop = cacheClient.queryWithLogicalExpire(RedisConstants.CACHE_SHOP_KEY,id, Shop.class,this::getById,20L,TimeUnit.SECONDS);

        if (shop == null) {
            return Result.fail("店铺不存在");
        }

        // 返回店铺信息
        return Result.ok(shop);
    }


    public void saveShop2Redis(Long id,Long expireSeconds) throws InterruptedException {
        // 1.查询店铺数据
        Shop shop = getById(id);
        Thread.sleep(200);
        // 2.封装成逻辑过期
        RedisData redisData = new RedisData();
        redisData.setData(shop);
        redisData.setExpireTime(LocalDateTime.now().plusSeconds(expireSeconds));
        // 3.写入到Redis
        stringRedisTemplate.opsForValue().set(RedisConstants.CACHE_SHOP_KEY + id,JSONUtil.toJsonStr(redisData));
    }


    @Override
    @Transactional
    public Result updateShop(Shop shop) {
        // 添加事务，支持回滚
        if (shop.getId() == null) {
            return Result.fail("店铺id不能为空");
        }

        // 1.更新数据库
        updateById(shop);

        // 2.删除缓存
        stringRedisTemplate.delete(RedisConstants.CACHE_SHOP_KEY + shop.getId());

        return Result.ok();
    }

    @Override
    public Result queryShopByType(Integer typeId, Integer current, Double x, Double y) {
        // 1.判断是否需要根据坐标查询
        if(x == null || y == null){
            Page<Shop> page = query().eq("type_id", typeId).page(new Page<>(current, SystemConstants.DEFAULT_PAGE_SIZE));
            return Result.ok(page.getRecords());
        }
        // 2.计算分页参数
        int from = (current - 1) * SystemConstants.DEFAULT_PAGE_SIZE;
        int end = current * SystemConstants.DEFAULT_PAGE_SIZE;

        // 3.查询Redis，根据距离排序、分页，结果：shopId、distance
        String key = RedisConstants.SHOP_GEO_KEY + typeId;
        GeoResults<RedisGeoCommands.GeoLocation<String>> results = stringRedisTemplate.opsForGeo()
                .search(key,
                        GeoReference.fromCoordinate(x, y),
                        new Distance(5000),
                        RedisGeoCommands.GeoSearchCommandArgs.newGeoSearchArgs().includeDistance().limit(end)
                );

        /// 4.解析ID
        if(results == null){
            return Result.ok(Collections.emptyList());
        }

        List<GeoResult<RedisGeoCommands.GeoLocation<String>>> list = results.getContent();

        if(list.size() <= from){
            return Result.ok(Collections.emptyList());
        }

        List<Long> ids = new ArrayList<>(list.size());
        Map<String,Distance> distanceMap = new HashMap<>(list.size());
        list.stream().skip(from).forEach(result -> {
            // 获取店铺ID
            String shopIdStr = result.getContent().getName();
            ids.add(Long.valueOf(shopIdStr));
            Distance distance = result.getDistance();
            distanceMap.put(shopIdStr,distance);
        });
        // 5.根据ID查询出shop
        String idStr = StrUtil.join(",", ids);
        List<Shop> shops = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list();

        for (Shop shop : shops) {
            shop.setDistance(distanceMap.get(shop.getId().toString()).getValue());
        }
        // 6.返回
        return Result.ok(shops);
    }
}
